Molecular insights into the behaviour of bile salts at interfaces: a key to their role in lipid digestion

Pabois, O., Lorenz, C. D., Harvey, R. D., Grillo, I., Grundy, M. M.-L., Wilde, P. J., Gerelli, Y. and Dreiss, C. A. (2019) Molecular insights into the behaviour of bile salts at interfaces: a key to their role in lipid digestion. Journal of Colloid and Interface Science, 556. pp. 266-277. ISSN 0021-9797 doi: 10.1016/j.jcis.2019.08.010

Abstract/Summary

Hypotheses. Understanding the mechanisms underlying lipolysis is crucial to address the ongoing obesity crisis and associated cardiometabolic disorders. Bile salts (BS), biosurfactants present in the small intestine, play key roles in lipid digestion and absorption. It is hypothesised that their contrasting functionalities – adsorption at oil/water interfaces and shuttling of lipolysis products away from these interfaces – are linked to their structural diversity. We investigate the interfacial films formed by two BS, sodium taurocholate (NaTC) and sodium taurodeoxycholate (NaTDC), differing by the presence or absence of a hydroxyl group on their steroid skeleton. Experiments. Their adsorption behaviour at the air/water interface and interaction with a phospholipid monolayer – used to mimic a fat droplet interface – were assessed by surface pressure measurements and ellipsometry, while interfacial morphologies were characterised in the lateral and perpendicular directions by Brewster angle microscopy, X-ray and neutron reflectometry, and molecular dynamics simulations. Findings. Our results provide a comprehensive molecular-level understanding of the mechanisms governing BS interfacial behaviour. NaTC shows a higher affinity for the air/water and lipid/water interfaces, and may therefore favour enzyme adsorption, whereas NaTDC exhibits a higher propensity for desorption from these interfaces, and may thus more effectively displace hydrolysis products from the interface, through dynamic exchange.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/85434
Identification Number/DOI	10.1016/j.jcis.2019.08.010
Refereed	Yes
Divisions	Life Sciences > School of Agriculture, Policy and Development > Department of Animal Sciences > Animal, Dairy and Food Chain Sciences (ADFCS)- DO NOT USE
Publisher	Elsevier
Download/View statistics	View download statistics for this item